Auto merge of #120522 - Nadrieril:rollup-zexjiyc, r=Nadrieril

Rollup of 9 pull requests

Successful merges:

 - #120207 (check `RUST_BOOTSTRAP_CONFIG` in `profile_user_dist` test)
 - #120321 (pattern_analysis: cleanup the contexts)
 - #120355 (document `FromIterator for Vec` allocation behaviors)
 - #120430 (std: thread_local::register_dtor fix proposal for FreeBSD.)
 - #120469 (Provide more context on derived obligation error primary label)
 - #120470 (Mark "unused binding" suggestion as maybe incorrect)
 - #120472 (Make duplicate lang items fatal)
 - #120495 (Remove the `abi_amdgpu_kernel` feature)
 - #120501 (rustdoc: Correctly handle attribute merge if this is a glob reexport)

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_codegen_cranelift/src/abi/mod.rs

@@ -56,11 +56,7 @@ pub(crate) fn conv_to_call_conv(sess: &Session, c: Conv, default_call_conv: Call
             sess.dcx().fatal("C-cmse-nonsecure-call call conv is not yet implemented");
         }
 
-        Conv::Msp430Intr
-        | Conv::PtxKernel
-        | Conv::AmdGpuKernel
-        | Conv::AvrInterrupt
-        | Conv::AvrNonBlockingInterrupt => {
+        Conv::Msp430Intr | Conv::PtxKernel | Conv::AvrInterrupt | Conv::AvrNonBlockingInterrupt => {
             unreachable!("tried to use {c:?} call conv which only exists on an unsupported target");
         }
     }

compiler/rustc_codegen_llvm/src/abi.rs

@@ -590,7 +590,6 @@ impl From<Conv> for llvm::CallConv {
             Conv::Cold => llvm::ColdCallConv,
             Conv::PreserveMost => llvm::PreserveMost,
             Conv::PreserveAll => llvm::PreserveAll,
-            Conv::AmdGpuKernel => llvm::AmdGpuKernel,
             Conv::AvrInterrupt => llvm::AvrInterrupt,
             Conv::AvrNonBlockingInterrupt => llvm::AvrNonBlockingInterrupt,
             Conv::ArmAapcs => llvm::ArmAapcsCallConv,

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -106,7 +106,6 @@ pub enum CallConv {
     X86_Intr = 83,
     AvrNonBlockingInterrupt = 84,
     AvrInterrupt = 85,
-    AmdGpuKernel = 91,
 }
 
 /// LLVMRustLinkage

compiler/rustc_feature/src/removed.rs

@@ -32,6 +32,8 @@ declare_features! (
     // feature-group-start: removed features
     // -------------------------------------------------------------------------
 
+    /// Allows using the `amdgpu-kernel` ABI.
+    (removed, abi_amdgpu_kernel, "CURRENT_RUSTC_VERSION", Some(51575), None),
     (removed, advanced_slice_patterns, "1.0.0", Some(62254),
      Some("merged into `#![feature(slice_patterns)]`")),
     (removed, allocator, "1.0.0", None, None),

compiler/rustc_feature/src/unstable.rs

@@ -321,8 +321,6 @@ declare_features! (
     // feature-group-start: actual feature gates
     // -------------------------------------------------------------------------
 
-    /// Allows using the `amdgpu-kernel` ABI.
-    (unstable, abi_amdgpu_kernel, "1.29.0", Some(51575)),
     /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
     (unstable, abi_avr_interrupt, "1.45.0", Some(69664)),
     /// Allows `extern "C-cmse-nonsecure-call" fn()`.

compiler/rustc_middle/src/ty/layout.rs

@@ -1247,7 +1247,6 @@ pub fn fn_can_unwind(tcx: TyCtxt<'_>, fn_def_id: Option<DefId>, abi: SpecAbi) ->
         PtxKernel
         | Msp430Interrupt
         | X86Interrupt
-        | AmdGpuKernel
         | EfiApi
         | AvrInterrupt
         | AvrNonBlockingInterrupt

compiler/rustc_mir_transform/src/ffi_unwind_calls.rs

@@ -26,7 +26,6 @@ fn abi_can_unwind(abi: Abi) -> bool {
         PtxKernel
         | Msp430Interrupt
         | X86Interrupt
-        | AmdGpuKernel
         | EfiApi
         | AvrInterrupt
         | AvrNonBlockingInterrupt

compiler/rustc_passes/src/errors.rs

@@ -1739,7 +1739,7 @@ pub struct UnusedVariableTryPrefix {
 
 #[derive(Subdiagnostic)]
 pub enum UnusedVariableSugg {
-    #[multipart_suggestion(passes_suggestion, applicability = "machine-applicable")]
+    #[multipart_suggestion(passes_suggestion, applicability = "maybe-incorrect")]
     TryPrefixSugg {
         #[suggestion_part(code = "_{name}")]
         spans: Vec<Span>,
@@ -1778,7 +1778,7 @@ pub struct UnusedVarTryIgnore {
 }
 
 #[derive(Subdiagnostic)]
-#[multipart_suggestion(passes_suggestion, applicability = "machine-applicable")]
+#[multipart_suggestion(passes_suggestion, applicability = "maybe-incorrect")]
 pub struct UnusedVarTryIgnoreSugg {
     #[suggestion_part(code = "{name}: _")]
     pub shorthands: Vec<Span>,

compiler/rustc_passes/src/lang_items.rs

@@ -149,7 +149,9 @@ impl<'ast, 'tcx> LanguageItemCollector<'ast, 'tcx> {
                 }
             };
 
-            self.tcx.dcx().emit_err(DuplicateLangItem {
+            // When there's a duplicate lang item, something went very wrong and there's no value in recovering or doing anything.
+            // Give the user the one message to let them debug the mess they created and then wish them farewell.
+            self.tcx.dcx().emit_fatal(DuplicateLangItem {
                 local_span: item_span,
                 lang_item_name,
                 crate_name,

compiler/rustc_pattern_analysis/src/constructor.rs

@@ -163,7 +163,6 @@ use self::MaybeInfiniteInt::*;
 use self::SliceKind::*;
 
 use crate::index;
-use crate::usefulness::PlaceCtxt;
 use crate::TypeCx;
 
 /// Whether we have seen a constructor in the column or not.
@@ -818,21 +817,20 @@ impl<Cx: TypeCx> Constructor<Cx> {
 
     /// The number of fields for this constructor. This must be kept in sync with
     /// `Fields::wildcards`.
-    pub(crate) fn arity(&self, pcx: &PlaceCtxt<'_, Cx>) -> usize {
-        pcx.ctor_arity(self)
+    pub(crate) fn arity(&self, cx: &Cx, ty: &Cx::Ty) -> usize {
+        cx.ctor_arity(self, ty)
     }
 
     /// Returns whether `self` is covered by `other`, i.e. whether `self` is a subset of `other`.
     /// For the simple cases, this is simply checking for equality. For the "grouped" constructors,
     /// this checks for inclusion.
     // We inline because this has a single call site in `Matrix::specialize_constructor`.
     #[inline]
-    pub(crate) fn is_covered_by(&self, pcx: &PlaceCtxt<'_, Cx>, other: &Self) -> bool {
+    pub(crate) fn is_covered_by(&self, cx: &Cx, other: &Self) -> bool {
         match (self, other) {
-            (Wildcard, _) => pcx
-                .mcx
-                .tycx
-                .bug(format_args!("Constructor splitting should not have returned `Wildcard`")),
+            (Wildcard, _) => {
+                cx.bug(format_args!("Constructor splitting should not have returned `Wildcard`"))
+            }
             // Wildcards cover anything
             (_, Wildcard) => true,
             // Only a wildcard pattern can match these special constructors.
@@ -873,7 +871,7 @@ impl<Cx: TypeCx> Constructor<Cx> {
             (Opaque(self_id), Opaque(other_id)) => self_id == other_id,
             (Opaque(..), _) | (_, Opaque(..)) => false,
 
-            _ => pcx.mcx.tycx.bug(format_args!(
+            _ => cx.bug(format_args!(
                 "trying to compare incompatible constructors {self:?} and {other:?}"
             )),
         }
@@ -950,10 +948,10 @@ pub enum ConstructorSet<Cx: TypeCx> {
 /// of the `ConstructorSet` for the type, yet if we forgot to include them in `present` we would be
 /// ignoring any row with `Opaque`s in the algorithm. Hence the importance of point 4.
 #[derive(Debug)]
-pub(crate) struct SplitConstructorSet<Cx: TypeCx> {
-    pub(crate) present: SmallVec<[Constructor<Cx>; 1]>,
-    pub(crate) missing: Vec<Constructor<Cx>>,
-    pub(crate) missing_empty: Vec<Constructor<Cx>>,
+pub struct SplitConstructorSet<Cx: TypeCx> {
+    pub present: SmallVec<[Constructor<Cx>; 1]>,
+    pub missing: Vec<Constructor<Cx>>,
+    pub missing_empty: Vec<Constructor<Cx>>,
 }
 
 impl<Cx: TypeCx> ConstructorSet<Cx> {
@@ -962,7 +960,7 @@ impl<Cx: TypeCx> ConstructorSet<Cx> {
     /// or slices. This can get subtle; see [`SplitConstructorSet`] for details of this operation
     /// and its invariants.
     #[instrument(level = "debug", skip(self, ctors), ret)]
-    pub(crate) fn split<'a>(
+    pub fn split<'a>(
         &self,
         ctors: impl Iterator<Item = &'a Constructor<Cx>> + Clone,
     ) -> SplitConstructorSet<Cx>

compiler/rustc_pattern_analysis/src/lib.rs

@@ -6,6 +6,7 @@ pub mod errors;
 #[cfg(feature = "rustc")]
 pub(crate) mod lints;
 pub mod pat;
+pub mod pat_column;
 #[cfg(feature = "rustc")]
 pub mod rustc;
 pub mod usefulness;
@@ -67,8 +68,9 @@ use rustc_span::ErrorGuaranteed;
 
 use crate::constructor::{Constructor, ConstructorSet, IntRange};
 #[cfg(feature = "rustc")]
-use crate::lints::{lint_nonexhaustive_missing_variants, PatternColumn};
+use crate::lints::lint_nonexhaustive_missing_variants;
 use crate::pat::DeconstructedPat;
+use crate::pat_column::PatternColumn;
 #[cfg(feature = "rustc")]
 use crate::rustc::RustcMatchCheckCtxt;
 #[cfg(feature = "rustc")]
@@ -135,20 +137,6 @@ pub trait TypeCx: Sized + fmt::Debug {
     }
 }
 
-/// Context that provides information global to a match.
-pub struct MatchCtxt<'a, Cx: TypeCx> {
-    /// The context for type information.
-    pub tycx: &'a Cx,
-}
-
-impl<'a, Cx: TypeCx> Clone for MatchCtxt<'a, Cx> {
-    fn clone(&self) -> Self {
-        Self { tycx: self.tycx }
-    }
-}
-
-impl<'a, Cx: TypeCx> Copy for MatchCtxt<'a, Cx> {}
-
 /// The arm of a match expression.
 #[derive(Debug)]
 pub struct MatchArm<'p, Cx: TypeCx> {
@@ -175,15 +163,13 @@ pub fn analyze_match<'p, 'tcx>(
 ) -> Result<rustc::UsefulnessReport<'p, 'tcx>, ErrorGuaranteed> {
     let scrut_ty = tycx.reveal_opaque_ty(scrut_ty);
     let scrut_validity = ValidityConstraint::from_bool(tycx.known_valid_scrutinee);
-    let cx = MatchCtxt { tycx };
-
-    let report = compute_match_usefulness(cx, arms, scrut_ty, scrut_validity)?;
+    let report = compute_match_usefulness(tycx, arms, scrut_ty, scrut_validity)?;
 
     // Run the non_exhaustive_omitted_patterns lint. Only run on refutable patterns to avoid hitting
     // `if let`s. Only run if the match is exhaustive otherwise the error is redundant.
     if tycx.refutable && report.non_exhaustiveness_witnesses.is_empty() {
         let pat_column = PatternColumn::new(arms);
-        lint_nonexhaustive_missing_variants(cx, arms, &pat_column, scrut_ty)?;
+        lint_nonexhaustive_missing_variants(tycx, arms, &pat_column, scrut_ty)?;
     }
 
     Ok(report)

compiler/rustc_pattern_analysis/src/lints.rs

@@ -1,109 +1,24 @@
 use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
 use rustc_span::ErrorGuaranteed;
 
+use crate::constructor::Constructor;
 use crate::errors::{NonExhaustiveOmittedPattern, NonExhaustiveOmittedPatternLintOnArm, Uncovered};
-use crate::pat::PatOrWild;
-use crate::rustc::{
-    Constructor, DeconstructedPat, MatchArm, MatchCtxt, PlaceCtxt, RevealedTy, RustcMatchCheckCtxt,
-    SplitConstructorSet, WitnessPat,
-};
-
-/// A column of patterns in the matrix, where a column is the intuitive notion of "subpatterns that
-/// inspect the same subvalue/place".
-/// This is used to traverse patterns column-by-column for lints. Despite similarities with the
-/// algorithm in [`crate::usefulness`], this does a different traversal. Notably this is linear in
-/// the depth of patterns, whereas `compute_exhaustiveness_and_usefulness` is worst-case exponential
-/// (exhaustiveness is NP-complete). The core difference is that we treat sub-columns separately.
-///
-/// This must not contain an or-pattern. `expand_and_push` takes care to expand them.
-///
-/// This is not used in the usefulness algorithm; only in lints.
-#[derive(Debug)]
-pub(crate) struct PatternColumn<'p, 'tcx> {
-    patterns: Vec<&'p DeconstructedPat<'p, 'tcx>>,
-}
-
-impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
-    pub(crate) fn new(arms: &[MatchArm<'p, 'tcx>]) -> Self {
-        let patterns = Vec::with_capacity(arms.len());
-        let mut column = PatternColumn { patterns };
-        for arm in arms {
-            column.expand_and_push(PatOrWild::Pat(arm.pat));
-        }
-        column
-    }
-    /// Pushes a pattern onto the column, expanding any or-patterns into its subpatterns.
-    /// Internal method, prefer [`PatternColumn::new`].
-    fn expand_and_push(&mut self, pat: PatOrWild<'p, RustcMatchCheckCtxt<'p, 'tcx>>) {
-        // We flatten or-patterns and skip algorithm-generated wildcards.
-        if pat.is_or_pat() {
-            self.patterns.extend(
-                pat.flatten_or_pat().into_iter().filter_map(|pat_or_wild| pat_or_wild.as_pat()),
-            )
-        } else if let Some(pat) = pat.as_pat() {
-            self.patterns.push(pat)
-        }
-    }
-
-    fn head_ty(&self) -> Option<RevealedTy<'tcx>> {
-        self.patterns.first().map(|pat| *pat.ty())
-    }
-
-    /// Do constructor splitting on the constructors of the column.
-    fn analyze_ctors(
-        &self,
-        pcx: &PlaceCtxt<'_, 'p, 'tcx>,
-    ) -> Result<SplitConstructorSet<'p, 'tcx>, ErrorGuaranteed> {
-        let column_ctors = self.patterns.iter().map(|p| p.ctor());
-        let ctors_for_ty = &pcx.ctors_for_ty()?;
-        Ok(ctors_for_ty.split(column_ctors))
-    }
-
-    /// Does specialization: given a constructor, this takes the patterns from the column that match
-    /// the constructor, and outputs their fields.
-    /// This returns one column per field of the constructor. They usually all have the same length
-    /// (the number of patterns in `self` that matched `ctor`), except that we expand or-patterns
-    /// which may change the lengths.
-    fn specialize(
-        &self,
-        pcx: &PlaceCtxt<'_, 'p, 'tcx>,
-        ctor: &Constructor<'p, 'tcx>,
-    ) -> Vec<PatternColumn<'p, 'tcx>> {
-        let arity = ctor.arity(pcx);
-        if arity == 0 {
-            return Vec::new();
-        }
-
-        // We specialize the column by `ctor`. This gives us `arity`-many columns of patterns. These
-        // columns may have different lengths in the presence of or-patterns (this is why we can't
-        // reuse `Matrix`).
-        let mut specialized_columns: Vec<_> =
-            (0..arity).map(|_| Self { patterns: Vec::new() }).collect();
-        let relevant_patterns =
-            self.patterns.iter().filter(|pat| ctor.is_covered_by(pcx, pat.ctor()));
-        for pat in relevant_patterns {
-            let specialized = pat.specialize(ctor, arity);
-            for (subpat, column) in specialized.into_iter().zip(&mut specialized_columns) {
-                column.expand_and_push(subpat);
-            }
-        }
-        specialized_columns
-    }
-}
+use crate::pat_column::PatternColumn;
+use crate::rustc::{RevealedTy, RustcMatchCheckCtxt, WitnessPat};
+use crate::MatchArm;
 
 /// Traverse the patterns to collect any variants of a non_exhaustive enum that fail to be mentioned
 /// in a given column.
 #[instrument(level = "debug", skip(cx), ret)]
 fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
-    cx: MatchCtxt<'a, 'p, 'tcx>,
-    column: &PatternColumn<'p, 'tcx>,
+    cx: &RustcMatchCheckCtxt<'p, 'tcx>,
+    column: &PatternColumn<'p, RustcMatchCheckCtxt<'p, 'tcx>>,
 ) -> Result<Vec<WitnessPat<'p, 'tcx>>, ErrorGuaranteed> {
-    let Some(ty) = column.head_ty() else {
+    let Some(&ty) = column.head_ty() else {
         return Ok(Vec::new());
     };
-    let pcx = &PlaceCtxt::new_dummy(cx, &ty);
 
-    let set = column.analyze_ctors(pcx)?;
+    let set = column.analyze_ctors(cx, &ty)?;
     if set.present.is_empty() {
         // We can't consistently handle the case where no constructors are present (since this would
         // require digging deep through any type in case there's a non_exhaustive enum somewhere),
@@ -112,20 +27,20 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
     }
 
     let mut witnesses = Vec::new();
-    if cx.tycx.is_foreign_non_exhaustive_enum(ty) {
+    if cx.is_foreign_non_exhaustive_enum(ty) {
         witnesses.extend(
             set.missing
                 .into_iter()
                 // This will list missing visible variants.
                 .filter(|c| !matches!(c, Constructor::Hidden | Constructor::NonExhaustive))
-                .map(|missing_ctor| WitnessPat::wild_from_ctor(pcx, missing_ctor)),
+                .map(|missing_ctor| WitnessPat::wild_from_ctor(cx, missing_ctor, ty)),
         )
     }
 
     // Recurse into the fields.
     for ctor in set.present {
-        let specialized_columns = column.specialize(pcx, &ctor);
-        let wild_pat = WitnessPat::wild_from_ctor(pcx, ctor);
+        let specialized_columns = column.specialize(cx, &ty, &ctor);
+        let wild_pat = WitnessPat::wild_from_ctor(cx, ctor, ty);
         for (i, col_i) in specialized_columns.iter().enumerate() {
             // Compute witnesses for each column.
             let wits_for_col_i = collect_nonexhaustive_missing_variants(cx, col_i)?;
@@ -141,18 +56,17 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
     Ok(witnesses)
 }
 
-pub(crate) fn lint_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
-    cx: MatchCtxt<'a, 'p, 'tcx>,
-    arms: &[MatchArm<'p, 'tcx>],
-    pat_column: &PatternColumn<'p, 'tcx>,
+pub(crate) fn lint_nonexhaustive_missing_variants<'p, 'tcx>(
+    rcx: &RustcMatchCheckCtxt<'p, 'tcx>,
+    arms: &[MatchArm<'p, RustcMatchCheckCtxt<'p, 'tcx>>],
+    pat_column: &PatternColumn<'p, RustcMatchCheckCtxt<'p, 'tcx>>,
     scrut_ty: RevealedTy<'tcx>,
 ) -> Result<(), ErrorGuaranteed> {
-    let rcx: &RustcMatchCheckCtxt<'_, '_> = cx.tycx;
     if !matches!(
         rcx.tcx.lint_level_at_node(NON_EXHAUSTIVE_OMITTED_PATTERNS, rcx.match_lint_level).0,
         rustc_session::lint::Level::Allow
     ) {
-        let witnesses = collect_nonexhaustive_missing_variants(cx, pat_column)?;
+        let witnesses = collect_nonexhaustive_missing_variants(rcx, pat_column)?;
         if !witnesses.is_empty() {
             // Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns`
             // is not exhaustive enough.